A MODEL POTENTIAL FOR Ar-HCN
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Date
1989
Journal Title
Journal ISSN
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Publisher
Ohio State University
Abstract
In the original investigation of the ground vibrational state of the van der Waals molecule, Ar-HCN, much of the unusual behavior of this complex, including the large centrifugal distortion constant, sensitive to isotopic substitution, along with unexpected behavior of the average bending angle and the van der Waals bond length upon deuteration, was postulated to arise from very strong angular-radial coupling which might result from a double well $potential.^{1}$ This form of the potential was suggested by analogies to the very similar Ar-HCl complex and to the isoelectronic Ar-HCCH molecule. In a test of this hypothesis, we have used close-coupling calculations to adjust the parameters of such a model potential to reproduce the observed spectroscopic properties. Our ability to sucessfully model the seemingly mysterious behavior of this molecule with a simple potential energy surface based on chemical intuition lends support to the suggestions of the original experimental study, but does not exclude the possibility of a potential of a different form. Additional experimental evidence is required to place further restrictions on the precise form of the surface, and predictions concerning the location and properties of excited vibrational states are presented to facilitate such comparison.
Description
$^{1}$ K.R. Leopold, G.T. Fraser, F.J. Lin, D.D. Nelson, Jr., and W. Klemperer, J. Chem. Phys. 81, 4922 (1984).
Author Institution: Harvard-Smithsonian Center for Astrophysics; Department of Chemistry, Amherst College; Department of Chemistry, Harvard University
Author Institution: Harvard-Smithsonian Center for Astrophysics; Department of Chemistry, Amherst College; Department of Chemistry, Harvard University